• Identified predictive biomarkers that potentially correlate with treatment response
  • A novel drug quantification method in tumor cells revealed high drug uptake at the cellular level for the first time in clinical samples
  • Leveraging AI technology developed by Rakuten Institute of Technology Bengaluru, a part of the global R&D organization of Rakuten Group, Inc.

Newswise — SAN DIEGONov. 6, 2023 /PRNewswire/ -- Rakuten Medical, Inc., a global biotechnology company developing and commercializing precision, cell-targeted therapies based on its proprietary Alluminox™ platform today announced the presentation of two posters of AI-based analyses at the 38th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), held November 3-5, 2023, in San Diego, CA (SITC 2023). The posters present data that may be relevant to improved clinical outcomes with treatment based on Rakuten Medical's Alluminox™ platform (photoimmunotherapy).

The samples analyzed for these posters are from patients enrolled in an open-label Phase 1b/2 clinical trial (ASP-1929-181 study/ClinicalTrials.gov Identifier: NCT04305795) of ASP-1929 photoimmunotherapy in combination with anti-PD-1 for recurrent or metastatic head and neck squamous cell cancer or advanced or metastatic cutaneous squamous cell carcinoma. Promising early evaluation data from the ASP-1929-181 study* was presented at the American Head and Neck Society (AHNS) in July 2023 (Abstract #: S252). The studies presented at SITC 2023 utilized AI technology developed by Rakuten Institute of Technology Bengaluru, a part of Rakuten India Enterprise Private Limited and a branch of the global R&D organization of Rakuten Group, Inc., to further interpret the response data presented at AHNS. Rakuten Medical and Rakuten Institute of Technology Bengaluru have collaborated on AI-based analyses of patient samples since 2020.

* These preliminary findings may change upon completion of follow up and final data analysis.

Key findings presented at SITC 2023

Title: Development of an image-based tumor microenvironment analysis coupled with peripheral flow cytometry reveals a distinct immune cell phenotype in responder patients in the Phase 1b/2 study ASP-1929-181

Abstract #: 83

The first poster addresses immune characteristics between responders and non-responders who received ASP-1929 photoimmunotherapy. Potentially predictive immune biomarkers were identified using a combination of multiplex immunofluorescent imaging methods with AI-based quantification and flow cytometry analyses of peripheral blood. The study results suggest that lower frequencies of CD8+ T cells in the blood at screening correlate with treatment response. Interestingly, of CD8+ T cells in the blood, an increased frequency of PD-1 co-expression also correlates with treatment outcome. At the tumor, an increase in cytotoxic CD8+ T cells in all 22 analyzed patients was observed over the course of treatment, suggesting the induction of the immune response following photoimmunotherapy.

Title: Development of a novel, cellular-level drug uptake quantification pipeline for accurate quantification of fluorescence-conjugated therapeutics: Data from the Phase 1b/2 open-label study ASP-1929-181

Abstract #: 1307

The second poster describes the quantification of drug binding to target cells for ASP-1929 photoimmunotherapy. The preliminary data suggested that a modified drug quantification method using AI-based tumor detection and cell segmentation has the potential to accurately measure drug uptake in tumors at the cellular level. Using this method, high drug uptake (>50-100%) in tumors prior to light treatment was observed for the first time in the clinical samples. Understanding drug uptake levels could help support dose response analyses in future preclinical studies and clinical trials.

About Rakuten Medical, Inc.
Rakuten Medical, Inc. is a global biotechnology company developing and commercializing precision, cell targeting therapies based on its proprietary Alluminox™ platform, which, in pre-clinical studies, has been shown to induce rapid and selective cell killing and tumor necrosis. Alluminox therapies have not yet been approved outside of Japan. Rakuten Medical is committed to its mission to conquer cancer by delivering our innovative treatments as quickly as possible to as many patients as possible all over the world. The company has offices in 6 countries, including the United States, where it is headquartered, Japan, the Netherlands, Taiwan, Switzerland and India. For more information, visit www.rakuten-med.com.

About Alluminox™ platform 
The Alluminox™ platform is an investigational technology platform based on a cancer therapy called photoimmunotherapy, which was developed by Dr. Hisataka Kobayashi and team from the National Cancer Institute in the United States. Rakuten Medical is developing the Alluminox platform as a technology consisting of a drug, device, and other related components. The drug component of the platform consists of a targeting moiety conjugated with one or more dyes leading to selective cell surface binding. The device component consists of a light source that locally illuminates the targeted cells with light to transiently activate the drug. Pre-clinical data have shown that this activation elicits rapid and selective necrosis of targeted cells through a biophysical process that compromises the membrane integrity of the targeted cells. Therapies developed on the Alluminox platform may also result in local and systemic innate and adaptive immune activation due to immunogenic cell death of the targeted cancer cells and/or the removal of targeted immunosuppressive cells within the tumor microenvironment. Outside of Japan, Alluminox therapies have not yet been approved by any regulatory authority.

About ASP-1929
Rakuten Medical's first pipeline drug developed on its Alluminox™ platform is ASP-1929, an antibody-dye conjugate comprised of the antibody cetuximab and IRDye® 700DX, a light activatable dye. ASP-1929 binds to epidermal growth factor receptor (EGFR), a cancer antigen expressed in multiple types of solid tumors, including head and neck, breast, lung, colorectal, prostate and pancreatic cancers. After binding to cancer cells, ASP-1929 is locally activated by   illumination with red light (690 nm), emitted by a laser device system to produce a photochemical reaction. This reaction is believed to cause damage to the membrane of cancer cells, leading to selective necrosis of cancer cells. ASP-1929 received Fast Track designation from the U.S. Food and Drug Administration (FDA) in January 2018, and is currently under investigation in a global Phase 3 clinical trial for recurrent head and neck cancer. In Japan, ASP-1929 received marketing approval from the Japanese Ministry of Health, Labor, and Welfare for unresectable locally advanced or recurrent head and neck cancer in September 2020, under the Sakigake Designation System and the Conditional Early Approval System. Outside of Japan, ASP-1929 has not yet been approved by any regulatory authority.

Forward Looking Statements 
This press release contains forward looking statements that correspond to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements include various risks, uncertainties, and assumptions that may cause Rakuten Medical's business plans and results to differ from the anticipated results and expectations expressed in these statements. These "forward looking statements" contain information about the status and development of our products, including the Alluminox™ platform, as well as other regulatory and marketing authorization efforts, the potential benefits, efficacy, and safety of therapies created using the Alluminox platform, and the status of regulatory filings. The approval and commercial success of the product may not be achieved. Forward looking statements relate to the potential benefits, efficacy, and safety of our therapies, and the status of regulatory filings. Such statements may include words such as "expect," "believe," "hope," "estimate," "looks as though," "anticipate," "intend," "may," "suggest," "plan," "strategy," "will," and "do", and are based on our current beliefs. In addition, this press release uses terms such as "important," "notable," and "abnormal" to express opinions about clinical trial data. Ongoing clinical trial studies include various risks and uncertainties, in particular, problems that arise during the manufacturing stage of our therapies, the occurrence of adverse safety events, situations in failure to demonstrate therapeutic benefits, and other various risks and uncertainties, both reasonable and unreasonable. For this reason, actual results, including regulatory approvals and uncertainties in the commercialization process of our therapies, may differ from published information. Except to the extent required by applicable law, we undertake no obligation to publicly update this or any other forward-looking statement, whether because of new information, future developments or events, changes in assumptions, changes in the factors affecting forward-looking statements. If one or more forward-looking statement(s) is updated, no inference should be drawn that additional updates will be made to those or other forward-looking statements.